Audit
Understand the current system and dependencies before changing architecture.
Controlled change
Move systems without treating production as a test environment.
Implementation and migration work should use audits, backups, staging, validation, rollback planning and controlled production promotion.
Backup
Create and validate recovery material before migration or major upgrades.
Staging
Rehearse changes away from production whenever the scope justifies it.
Controlled Promotion
Move validated changes into production with rollback and regression protection.